Biomedical Frontiers: SPRING/SUMMER 1997, Vol.4, No.3
Better Vascular Connections

The arterial ostomizer allows the surgeon to reliably cut a precise hole in the wall of a blood vessel.

First, the surgeon uses the knife to make a one-half millimeter slit in the wall of the blood vessel. The surgeon then extends the T-shaped blade from the bottom of the ostomizer and inserts the blade through the slit into the lumen of the blood vessel. The surgeon then begins the cut by rotating the handle of the T-shaped blade while closing the ostomizer. The result is a precise opening in the wall of the blood vessel as the T-shaped blade presses the vessel wall to meet the tapered end of the cylinder. The blade retracts completely to remove the cut-out portion of the blood vessel wall. Illustrations Graham Roberts with Howard Roberts

innovations in microsurgery allow surgeons to skillfully repair smaller and smaller tissue structures. Two CPMC researchers have invented a device that makes it easier for surgeons to precisely connect blood vessels of varying sizes.

"In microsurgery, you often transfer tissue from one part of the body to another," says Dr. David T.W. Chiu, the Thomas S. Zimmer Professor and chief of plastic surgery and co-inventor of the "arterial ostomizer." To keep the transferred tissue alive, the surgeon must connect the tissue's blood vessels to vessels in the area receiving the transplant. Ideally, the surgeon looks for a blood vessel that matches the size of the ones in the transplanted tissue. If a vessel of the proper caliber is unavailable, the surgeon must then connect two vessels of different sizes by making a hole in the larger vessel, inserting the smaller vessel, and sewing the two together.

The problem with this method is that the size of the hole made in the larger vessel must perfectly match the size of the vessel to be transplanted. "If one has to create a hole as small as 1 millimeter, then even for the most experienced surgeon it is a difficult task," says Dr. Chiu. The need to cut the hole by hand limits the size of blood vessels that can be sewn in this manner to about 1 millimeter. Surgeons would like to connect blood vessels as small as one-half millimeter in diameter, and now the arterial ostomizer may help them do that.

The ostomizer, a patented device, is the collaborative effort of Dr. Chiu and Heinz D. Rosskothen. Mr. Rosskothen is director of ophthalmic instrumentation at Edward S. Harkness Eye Institute and in Columbia's Department of Ophthalmology.

The ostomizer is a hollow cylinder with a tapered cutting edge at one end. Mounted inside the cylinder is a retractable rotating T-shaped cutting blade. The cutting plane is where the T-shaped blade opposes the tapered end of the cylinder.

Dr. Chiu and Mr. Rosskothen are continuing to develop the ostomizer. "This device has a potentially wide application in microsurgery as well as in vascular surgery," says Dr. Chiu.